Process and apparatus for making paper



Nov. 6, 1928. 1,690,402

.1. c. CORCORAN PROCESS AND APPARATUS Foi i MAKING PAPER Filed Oct. 14, 1927 I z Sheets-Sheet 1 ATTORNEY Nov. 6, 1928.

J. C. CORCORAN PROCESS AND APPARATUS FOR MAKING PAPER Filed 001;. 14, 1927 2 Sheets-Sheet ATTORNEY R O T N E V m Patented Nov. 6, 1928.

UNITED STATES PATENT OF Fl CE.

JOHN c. CORCORAN, or WORCESTER, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGN- MENTS, To ARGY ran-HEATING CORPORATION, or NIAGARA FALLS, NEW YORK,

A CORPORATION OF NEW YORK.

PROCESS AND APPARATUS FOR MAKING PAPER.

Application filed October 14, 1927. Serial No. 226,111.

J This invention relates to a method of and apparatus for making paper.

The invention has for an object to'provide a novel method of and apparatus for making paper, by which superior paper may be produced more economically than with any of the existing paper machines or in accordance with any of the known methods of making paper of which I am aware.

With this object in view, the invention consists in the paper making machine and in the method of making paper hereinafter described and particularly defined in the claims at the end of this specification.

In the drawings illustrating the preferred form of paper machine for practicing the present. process, Figure 1 is a plan view and Fig. 2 a side elevation of the wet end of the machine; Figs. 3 and 4 are plans and side elevations respectively of the dry end of the paper making machine shown in Figs 1 and 2; Fig. 5 is a detail in plan, and Fig. 6 a side elevation of a novel portion of the machine, to be referred to; and Fig. 7 is a sectional detail of one of the conditioning drums shown in Figs. 5 and 6.

In the ordinary Fourdrinier paper making machine, the paper stock is caused tofiow onto the Fourdrinier wire where the web is formed and a portion of the water extracted by the passage of the web over the usual suction boxes. Thereafter the web is conducted upon a felt support between a pair of Squeeze or pressure rollers by which ad ditional water is'mechanically pressed from the web. The web is then conducted upon additional felts through one or more additional sets of pressure rollers which function to remove additional quantities of water by mechanically pressing the same from the web.

' From the last presser roll the web is conwhich serve to evaporate additional ducted over and around a set ofsteam drums quantities of water from the web.

In practice the ordinary paper making machines are operated at as high a speed as is practicable in order that maximum production may be obtained. Prior to the present invention the most efficient removal of moisture from the wet web by mechanical pressure during therapid passageof the web through the wet pressing apparatus has left the web as. it passes onto the driers, containing about 1 tons of water for each ton' .which the paper machines of finished paper. This necessitated the evaporation by the driers of practically 1 tons of water to each ton of paper, and this condition has limited the possible speed at may be run.

In accordance with the present process, and in the preferred paper machine embodying the present invention, the wet web of paper during its passage through the wet pressing apparatus is treated to diminishthe surface tension of the water within the web so that it is possible to remove by mechanical pressure a much larger amount of water than has heretofore been possible, with the result that during the passage of the web overthe driersa diminished amount of water is required to be evaporated. It has been found in embodying the present invention and practicing the present process, it is possible to remove sufficient, moisture by mechanical pressure such that the web as it passes onto the driers contains only approximately one ton of water to each ton of finished paper, and as a direct result of this it has been found to be practicable to increase the speed of op- .v eration of the machine approximately 50%. In addition paper made in accordance with the present process and upon the present machine appearsto' possess important characteristics which renderit more suitable for Various purposes thanv similar paper made' upon other types of machines.

I have discovered that the surface tension of the water contained in the paper web may be effectively diminished by heating the web and the water contained therein, up to a fairly high temperature, preferably about 150.

practice that in a paper machine F. When the web in this condition is then.

passed through a pair of squeeze rolls it is possible to mechanically press out a much greater amount of water than has heretofore been possible. In practice I have found it necessary, in order to obtain any ap reciable diminishing of the surface tension of the water in a web travelling. at the relatively high speed at which it is desirable to run the web in the commercial production of paper, to'

simultaneously heat the web on both sides or surfaces thereof, with the possible exception that when operating upon very thin paper, such as tissue paper, heating upon one surface may sufiice, although better results are obtained by the simultaneous heating of both surfaces. I have also discovered that it is necessary when operating upon papers containing any size, such as rosin size, that the surface of the paper should be chilled as the web is passed through the squeeze rolls, and in practice I prefer to run the hot paper web through a pair of squeeze rolls the upper of which is water cooled. The cli'ect of the cold squeeze rolls prevents sticking of the web to the squeeze rolls, and in addition serves to lay the fiber of the paper, producing a superior paper.

Referring now to the drawings, which illustrate a paper machine of the Fourdrinier type embodying the present invention, 10 represents the usual Fourdrinicr wire which runs around the usual supporting rollers 12, 13, one of which 13 is driven through gearing connections from a driven pulley in the manner diagrammatically illustrated in Fig. 1. The machine is also providedwith the usual deckle straps 14 and with the usual suction boxes 15 for removing part of the water during the formation of the web. The pulp stock flows from the usual flow box 18 onto the screen 10 during the operation of the machine. The machine is also provided with the-usual couch roll 16 and the details and mode of operation of the parts thus far described may and preferably will comprise those of the corresponding parts of the wellknown Fourdrinier paper making machine.

From the couch roll 16 the web of paper is conducted upon a supporting felt 20 of usual construction to between the first set of presser rolls 22, 23, which operate to mechanically squeeze out by their pressing action a portion of the moisture from the web. The Web is then conducted by the endless felt 20 to a second endless felt 25 which operatively supports the wet web of paper and is arranged to conduct it between a second set of presser rolls 26, 27 (see Fig. 4) which operate to me chanically ueeze additional quantities of water from t e web. From the presser rolls 26, 27, the web is conducted around a guiding roll 29 and over and in contact with a steam drum 31 around a. portion of the periphery of the same, thence around a second steam drum 32 arranged with respect to the first steam drum whereby the opposite side of the web is brought into contact with the drum. From the steam drum 32 the web is conducted around a third steam drum 33 arranged whereby the first side of the web is brought into contact with the drum.

Referring now again to Fig. 4, after the web leaves the heating drum 33, itis caused to pass around a guide roller 31 and is caused to passbetween the third set of presser rollers 35, 36, being operatively supported during the pressing operation upon a felt 40. After leaving the felt 40, the web is delivered onto another felt 42 by which it is conducted around a series of driers 44 of usual construction for the removal of the final moisture by evaporation. In practice I prefer that the upper presser roll 35, of the last set of wet presser rolls 35, 36, be Water cooled, and accordingly the presser roll 35 is provided with suitable connections 39, 41 for permitting the circulation therethrough of cold water.

The heating drums 31, 32 33 may and preferably will comprise cylindrical steel drums, the details and construction of which are illustrated in Figs. 5, 6 and 7, each having a hub 60 bolted or otherwise secured to the end of the drum and by which the drum is operatively journalled in bearings 62 in supporting standards or frames 63. The drums 31, 32, 33 are arranged to be driven at the same peripheral speed by cooperating gears 64, 65, 66 secured upon the ends of one set of hubs 60 and through a pinion 67 meshing with one of the gears 66, and itself driven from any convenient source of power. Provision is made for heating each drum, and for this purpose the hubs 60 are made hollow and steam is introduced into each drum from a source of supply through the inlet pipe 70, fitting 72, and through the exhaust pipe 76. The fitting 72 is connected by a suitable fitting 77 and packing 78 to permit the hub to be rotated While maintaining the steam-tight joint.-

For all grades of paper I believe it to be necessary and certainly desirable in all instances, possibly with the exception of the manufacture of thin tissue paper, that the rapidly travelling web of paper be subjected to simultaneous heating on both surfaces of the web. In some instances on certain grades of paper two steam drums may be used, but in most instances I prefer to utilize at least three such drums in order that the temperature of the web and of the water contained therein may be raised sufficiently to materially lower the surface tension of the water and enable the subsequent passage of the web through the last set of presser rolls to mechanically squeeze out a much greater volume of water than has heretofore been possible. For example, it has been found in practice that it is desirable to heat up the web and the water contained therein to'a temperature of approximately 150 during the passage of the web from the second to the third 'set of presser rolls, and under these condiamount of moisture to be evaporated per ton of paper represent a real saving in the amount of steam consumed in the operation of the machine. As a result of the diminished work required to be done by the driers it has been found practicable to increase the speed of peration of the machine up to approximately of the maximum speed heretofore obtained.

In order to prevent adhesion of the hot paper to the last set of presser rolls, I have ound it desirable to run a cold roll as the upper presser roll. This is particularly true in those grades of paper in which a sizing material is employed, such as a rosin size, and it is necessary to do this because of the relativel high temperature of the Web when passlng through these rolls. The effect of chilling the surface of the pa er by the cold presser roll appears to be of a vantage in the manufacture of certain grades of paper in that it appears to lay the fibers and to impart to the surface of-the paper a superior finish. Referring now to Fig, 4, it will be observed that the conditioning drums 31, 32, 33, constitute a unitary structure which lends itself particularly to being interposed between the second and third sets of presser rolls of the wet pressing apparatus of the ordinary Fourdrinier paper machine, without materially altering or disturbing the general horizontal course of travel of the web of paper. As a result existing paper machines may be converted to operate in accordance with the resent invention withminimum expense o installation and alteration. In addition the extraction of the water by the second and third sets of presser rolls 26, 27 and 35, 36, takes place in the usual way, with no liability of the extracted water dripping or running down onto the web, so that the general arrangement of these presser rolls may be preserved by the interposition of the conditioning drums 31, 32 and 33 in the manner indicated diagrammatically in Fig. 4. This arrangement has been found conducive to most satisfactory commercial paper makmg.

It is preferred to interpose the condition ing drums 31, 32, 33, between the second and third presser rolls of the ordinary paper machine, but it is to be understood that the invention is not limited to such structure,'and

while the preferred apparatus for practicin the present process has been illustrated an described, it is to be understood that the invention may be embodied'in other forms of a paratus within the scope of the following c aims.

Having thus described the invention what is claimed is 1. In a paper making machine, in combination, means for forming the web from the aper stock, means for mechanically extractmg moisture from the web including two sets v vided with a felt running-between the cooperating presser rolls, means for causing the 5 web to pass between the first set of presser rolls while supported upon said felt, and a plurality of heating drums around which the web is led in passing from one set of presser rolls to the other, to cause simultaneous engagement of opposite sides of the web with a eating drum, and means for conducting the web thereafter through the second set of presser rolls while operatively. supported upon the felt.

2. In a paper making machine, in combination, means for forming the web from the paper stock, two sets of presser rolls spaced apart, a felt running betweemeach set of presser rolls and upon which the web is suppaper stock, passing the wet web while supported upon the felt between a pair of presser rolls, then simultaneously Sub ecting the opposite surfaces of the paper web to sufficient heating to materially decrease the surface tension of the water within the web, thereafter passing the web through an additional set of presser rolls while the web is supported I upon the felt, and then passing the web over the usual driers. I

4. A rocess for making paper which consists in rst forming the paper web from the paper stock, passing the web while supported upon a felt through a pair of coo crating presser rolls, leading the paper-web rom the presser rolls over and around a plurality of eating drums to contact both sides of the web with a heating drum, and then passing the web while in its heated condition and supported upon the felt, through a second set of presser rolls, and thenpassing the web over the usual driers. 7

5. In the process of making paper on a paper machine, the steps which comprise the assingof the wet web of paper after its ormation through the next to the last set of presser rolls while the web is supported u on a felt, then subjecting opposite surfaces of the web to heat during the interval thatit is passing from said presser roll to the last.

set of presser rolls, and thereafter passing the web through the last set of presser rolls while op'eratively supporting it upon a felt.

6. The combinationwith the last two sets of presser rolls of the wet pressing apparatus of a paper machine, of a pluralit o heating drums located between said set of presser rolls and over and between which the web of paper is conducted to be heated upon its opposite surfaces for the purpose specified, said presser rolls being located with respect to the travel of the Web whereby to avoid liability of the extracted water coming in contact with the web.

7. In a paper making machine, in combination, two sets of presser rolls spaced apart, the second set of presser rolls being provided with a water cooled roll, and means for heating the web of paper during its passage from the first to the second set of said presser rolls.

8. In a paper making machine, in combinat-ion, means for forming. the web from the paper stock, means for mechanically extracting water from the web including two sets of presser rolls, and a plurality of heating drums interposed between said sets of presser rolls and over and between, which the web is conducted in its travel from the first to the second set of presser rolls, one of the presser rolls of the second set being water cooled to chill the surface of the web for the purpose specified.

9. The process of making paper which con- ,sists in first forming a web from the paper stock, then mechanically extracting a part of the water from the web, then heating the opposite surfaces of the web to raise the temperature of the water within the web sufiiciently to materially decrease the surface tension thereof, and then subjecting the web in its heated condition to pressing to mechanically extract additional quantities of water therefrom, and thereafter drying the web.

10. The process of making paper which consists in first forming a web from the paper stock, then mechanically extracting a part of the water from the web, then heating the opposite surfaces of the web to raise the temperature of the water within the web sufiiciently to materially decrease the surface ten sion thereof, and then subjecting the web in its heated condition to combined chilling and pressing action for the purpose specified, and thereafter drying the web.

In testimony whereof I have signed my name to this specification.

JOHN c. coRcoRAN. 

